On 12 August 2016 at 13:18, Tom Yan <tom.ty89@xxxxxxxxx> wrote: > On 12 August 2016 at 10:01, Martin K. Petersen > <martin.petersen@xxxxxxxxxx> wrote: >> >> Again, the point of max_hw_sectors and max_dev_sectors is to enforce the >> hard limits of controller and device respectively. Nothing else. >> > > Sounds like libata-scsi is doing something wrong then. It should not > set max_hw_sectors to dev->max_sectors that is set by libata-core: > >> blk_queue_max_hw_sectors(q, dev->max_sectors); Though we'll still have to "abuse" max_hw_sectors for ATAPI class devices, since neither the SATL or sr cares about VPD. The only devices that need ATA_HORKAGE_MAX_SEC_LBA48 are ATAPI devices as well. > > but instead it should report it as Maximum Transfer Length and let sd > set it as max_dev_sectors: > >> put_unaligned_be32(dev->max_sectors, &rbuf[8]); > > While max_hw_sectors will be left untouched (in the case of AHCI, for > example, since its SCSI host template does not have max_sectors set; > so max_hw_sectors will be SCSI_DEFAULT_MAX_SECTORS). > > Although that means setting dev->max_sectors to a value larger than > 1024 will probably be a no-op, if that's really an issue, we should > have the host templates in libata updated. > > Make sense? -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
